The New Zealand utilities investor has sold it for £1 as the company continues to unload more airports from its portfolio.
Marko Bogoievski, chief executive of Infratil, says: “Recognising the importance of the airport to the local communities and regional and national economy, Infratil's preference has always been to secure a new owner with the capacity to support the future success of Glasgow Prestwick Airport.
"We believe that a Scottish government acquisition achieves that objective and Infratil Limited is very pleased to have successfully completed the transaction."
No other details of the sale were given, which follows Infratil’s sale of Manston Airport in Kent to co-founder of Stagecoach Ann Gloag for £1 and other adjustments worth around £350,000 in October.
Last year Glasgow Prestwick welcomed more than one million passengers and it is the fourth busiest airport in Scotland.